Apparatus for imprint lithography comprising a logic element configured to generate a fluid droplet pattern and a method of using such apparatus

ABSTRACT

An apparatus for imprint lithography can include a logic element configured to generate a fluid droplet pattern of fluid droplets of a formable material to be dispensed onto a substrate. The fluid droplet pattern includes an imprint field, wherein the imprint field has a side and a drop exclusion zone along the side, and the drop exclusion zone is narrower at a first point farther from the center of a side and wider at a second point closer to the center of the side. In another aspect, a method can be carried out using the apparatus. The apparatus and method can be useful in filling an imprint field with a formable material relatively quickly without extrusion defects or other complications.

FIELD OF THE DISCLOSURE

The present disclosure relates to apparatuses for imprint lithography,and more particularly to apparatuses including a logic element togenerate a fluid droplet pattern.

RELATED ART

Imprint lithography apparatuses and processes are useful in formingnanoscale patterns on semiconductor wafers in the fabrication ofelectronic devices. Such apparatuses and processes can include the useof fluid dispense systems for depositing a formable material, forexample, a polymerizable material, such as a resin or a resist, onto thewafer, using techniques such as fluid droplet dispense. The dispensedmaterial is contacted with an imprint template (or mold) having desiredpattern features and then solidified, forming a patterned layer on thewafer. Template feature fill rates and related defects are dependent, inpart, on template pattern feature density and orientation and thedroplet pattern arrangement, including the fluid droplet pitch.

Traditional fluid dispense systems permit have a rectilinear pattern offluid droplet. Such a pattern may take a significant amount of time toform properly features and a residual layer corresponding to a template.Thus, there continues to be an industry demand for droplet patternprocesses that allow for quicker times to form properly resist patterns.

SUMMARY OF THE DISCLOSED EMBODIMENTS

In an aspect, an apparatus for imprint lithography can include a logicelement configured to generate a fluid droplet pattern of fluid dropletsof a formable material to be dispensed onto a substrate, wherein thefluid droplet pattern includes an imprint field, wherein the imprintfield has a side and a drop exclusion zone along the side, and the dropexclusion zone is narrower at a first point farther from a center of theside and wider at a second point closer to the center of the side.

In an embodiment, the fluid droplet pattern is organized in rows,wherein each row includes a terminal fluid droplet along a boundary ofthe drop exclusion zone.

In a particular embodiment, a first terminal fluid droplet is along afirst row, and a second terminal fluid droplet is along a second row,the center of the side of the imprint field is closer to the secondterminal fluid droplet than to the first terminal fluid droplet, and thefirst terminal fluid droplet has a corresponding first DEE, and thesecond terminal fluid droplet has a corresponding second DEE that islonger than the first DEE.

In a more particular embodiment, the fluid droplet pattern is arrangedin rows that extend in a translating direction and has a translatingfluid droplet pitch, and a difference between the second and first DEEsis less than the translating fluid droplet pitch.

In another embodiment, an angle between the side of the imprint fieldand a length of a fluid dispenser is configured to be changed during apass or between different passes.

In a particular embodiment, a fluid dispense system comprises a firstfluid dispenser and a second fluid dispenser.

In a more particular embodiment, the first and second fluid dispensersare in different rotational directions with respect to the side of theimprint field.

In another more particular embodiment, the first fluid dispenser and thesecond fluid dispenser are along different sides of the imprint field.

In a further more particular embodiment, the first fluid dispenser andthe second fluid dispenser are along adjacent sides of the imprintfield.

In an even more particular embodiment, the first fluid dispenser has alength that lies along a first line, the second fluid dispenser has alength that lies along a second line, and the first and second linesintersect at an angle other than 90°.

In another aspect, an imprint lithography method can include generatinga fluid droplet pattern of fluid droplets of a formable material to bedispensed onto a substrate, wherein the fluid droplet pattern includesan imprint field, wherein: the imprint field has a side and a dropexclusion zone along the side; and the drop exclusion zone is narrowerat a first point farther from a center of the side and wider at a secondpoint closer to the center of the side; and dispensing fluid droplets ofthe formable material onto the substrate corresponding to the fluiddroplet pattern.

In an embodiment, dispensing the fluid droplets of the formable materialis performed during a single pass using a first fluid dispenser and asecond fluid dispenser that are in different rotational positions withrespect to each other.

In another embodiment, dispensing the fluid droplets of the formablematerial comprises dispensing a first set of the fluid droplets using afluid dispenser during a first pass; rotating the fluid dispenser, thesubstrate, or both; and dispensing a second set of the fluid dropletsusing the fluid dispenser during a second pass.

In still another embodiment, dispensing the fluid droplets of theformable material comprises dispensing a first set of the fluid dropletsusing a first fluid dispenser and a second set of fluid droplets using asecond fluid dispenser during a pass, and rotating the first fluiddispenser, the second fluid dispenser, the substrate or any combinationduring the pass.

In a further embodiment, the method of claim further comprises providingan apparatus having a fluid dispense system that includes a first fluiddispenser and a second fluid dispenser, wherein: the first fluiddispenser and the second fluid dispenser are oriented along adjacentsides of the imprint field before dispensing the fluid droplets; thefirst fluid dispenser has a length that lies along a first line; thesecond fluid dispenser has a length that lies along a second line; andthe first and second lines intersect at an angle other than 90°.

In a particular embodiment, dispensing the fluid droplets of theformable material comprises dispensing a first set of the fluid dropletsusing the first fluid dispenser, and dispensing a second set of thefluid droplets using the second fluid dispenser.

In another embodiment, generating the fluid droplet pattern is performedsuch that, wherein on an intra-row basis, fluid droplets from each offirst and second passes or different fluid dispensers along a row has apredetermined local volume of the formable material.

In a particular embodiment, the fluid droplets from the first and secondpasses meet at a junction that is spaced apart from a central portion ofthe imprint field.

In a further aspect, a method of manufacturing an article can include:providing a fluid dispense system having fluid dispense ports;generating a fluid droplet pattern of fluid droplets of a formablematerial to be dispensed onto a substrate, wherein the fluid dropletpattern includes an imprint field, wherein: the imprint field has a sideand a drop exclusion zone along the side; and the drop exclusion zone isnarrower at a first point farther from a center of the side and wider ata second point closer to the center of the side; and moving a substrateof the article and the fluid dispense ports relative to each other;dispensing fluid droplets of the formable material onto the substratecorresponding to the fluid droplet pattern; contacting the formablematerial with the template having a patterned surface; and curing theformable material to form a patterned layer corresponding to thepatterned surface of the template.

In an embodiment, the article includes an electronic device, and thesubstrate includes a semiconductor wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and are not limited in theaccompanying figures.

FIG. 1 includes an illustration of a side view of an exemplary imprintlithography system.

FIG. 2 includes an illustration of a fluid droplet pattern.

FIG. 3 includes an illustration of another fluid droplet pattern.

FIG. 4 includes an illustration of a side view of a portion of a fluiddispenser and fluid dispense ports.

FIG. 5 includes an illustration of a set of fluid dispensers and part ofa fluid droplet pattern for an imprint field having fluid droplets nearopposing sides of an imprint field.

FIG. 6 includes an illustration of a fluid dispenser and part of a fluiddroplet pattern for an imprint field having fluid droplets near opposingsides of an imprint field that can be generated using two dispensepasses.

FIG. 7 includes an illustration of a fluid dispenser and part of a fluiddroplet pattern for an imprint field having fluid droplets near opposingsides of an imprint field that can be generated using two dispensepasses.

FIG. 8 includes an illustration of fluid dispensers and part of a fluiddroplet pattern for an imprint field having fluid droplets near opposingsides of an imprint field that can be generated using two dispensepasses.

FIG. 9 includes an illustration of fluid dispensers and part of a fluiddroplet pattern for an imprint field having fluid droplets fromdifferent passes stitched together.

FIG. 10 includes an illustration of a fluid dispenser and a fluiddroplet pattern for an imprint field having fluid droplets whererotation in a Y-Z plane is used.

FIG. 11 includes an illustration of a fluid dispenser and a fluiddroplet pattern for an imprint field having fluid droplets whererotation in a Y-Z plane is used.

FIG. 12 includes an illustration of fluid dispensers and a fluid dropletpattern for an imprint field having fluid droplets where rotation in aY-Z plane is used.

FIG. 13 includes a flow chart of an exemplary method of forming anarticle, including generating a fluid droplet pattern using theapparatus of FIG. 1.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help improve understandingof embodiments of the invention.

DETAILED DESCRIPTION

The following description in combination with the figures is provided toassist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This focus is provided to assist in describing the teachingsand should not be interpreted as a limitation on the scope orapplicability of the teachings.

The term “terminal fluid droplet,” when a fluid droplet pattern isorganized in rows, columns, or rows and columns, is intended to mean afluid drop along such row or column that is closest to a side of animprint field. A row or column can have terminal fluid droplets atopposite ends of such row or column.

The term “drop edge exclusion” or “DEE” is intended to mean a shortestdistance between a terminal fluid droplet and its adjacent side of animprint field. Each side can have a plurality of DEEs with each DEEcorresponding to a row or column of fluid droplets.

The term “drop exclusion zone” or “DEZ” is intended to mean an area ofan imprint field defined by a side of the imprint field and a linepassing through centers of terminal fluid droplets that are closest tosuch side.

The term “pitch” is intended to mean a distance from a center of afeature to a center of a next adjacent feature. For a fluid dropletpattern, the fluid droplet pitch is a distance from the center of afluid droplet to the center of the next adjacent fluid droplet. InCartesian coordinates, a two-dimensional pattern (a pattern as seen froma top view) can have a pitch in the X-direction that corresponds to thedistance between the centers of the features as measured in theX-direction (X-direction pitch), and a pitch in the Y-direction thatcorresponds to the distance between the centers of the features asmeasured in the Y-direction (Y-direction pitch). The X-direction pitchmay be the same or different from the Y-direction pitch.

As used herein, velocity and motion may be described on a relativebasis. For example, object A and object B move relative to each other.Such terminology is intended to cover object A is moving, and object Bis not; object A is not moving, and object B is moving; and both ofobjects A and B are moving.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent not described herein, many details regarding specific materialsand processing acts are conventional and may be found in textbooks andother sources within the imprint and lithography arts.

A fluid droplet pattern can be formed that allows for quicker filling ofan imprint field without extrusion defects or other complications. In anaspect, an apparatus for imprint lithography can include a logic elementconfigured to generate a fluid droplet pattern of fluid droplets of aformable material to be dispensed onto a substrate. The fluid dropletpattern can include an imprint field, wherein the imprint field has aside and drop exclusion zone along the side. The drop exclusion zone canbe narrower at a first point farther from a center of the side and widerat a second point closer to the center of the side. In another aspect,the apparatus can be used is performing a method to form the fluiddroplet pattern on the substrate.

Details regarding the apparatus and method are better understood afterreading this specification in conjunction with figures. The descriptionbelow is meant to illustrate embodiments and not limit the scope of thepresent invention, which is defined in the appended claims.

Referring to FIG. 1, a lithographic system 10 in accordance with anembodiment described herein can be used to form a relief pattern on asubstrate 12. The substrate 12 may be coupled to a substrate chuck 14.As illustrated, the substrate chuck 14 is a vacuum chuck; however, inother embodiments the substrate chuck 14 may be any chuck includingvacuum, pin-type, groove-type, electrostatic, electromagnetic, or thelike. The substrate 12 and substrate chuck 14 may be further supportedby a stage 16. The stage 16 may provide translating or rotational motionalong the X-, Y-, or Z-directions. The stage 16, substrate 12, andsubstrate chuck 14 may also be positioned on a base (not illustrated).

Spaced-apart from the substrate 12 is a template 18. The template 18 caninclude a body having a first side and a second side with one sidehaving a mold 20 extending therefrom towards the substrate 12. The mold20 is sometimes referred to as a mesa. In an embodiment, the template 18can be formed without a mold 20.

The template 18, mold 20, or both may be formed from such materialsincluding fused-silica, quartz, silicon, organic polymers, siloxanepolymers, borosilicate glass, fluorocarbon polymers, metal, hardenedsapphire, other similar materials, or any combination thereof. Thetemplate 18 and mold 20 can include a single piece construction.Alternatively, the template 18 and mold 20 can include separatecomponents coupled together. As illustrated, an imprint surface 22 ofthe mold 20 includes features defined by spaced-apart recesses 24 andprotrusions 26. The imprint surface 22 may define any original patternthat forms the basis of a pattern to be formed on the substrate 12. Inanother embodiment, the imprint surface 22 can be a blank, that is, theimprint surface 22 does not have any recesses or protrusions.

The template 18 can be coupled to a chuck 28. The chuck 28 can beconfigured as vacuum, pin-type, groove-type, electrostatic,electromagnetic, or another similar chuck type. In an embodiment, thechuck 28 may be coupled to an imprint head 30 such that the chuck 28 orimprint head 30 can facilitate movement of the template 18.

The lithographic system 10 can further include a fluid dispense system32 used to deposit a formable material 34 on the substrate 12. Forexample, the formable material 34 can include a polymerizable material,such as a resin. The formable material 34 can be positioned on thesubstrate 12 in one or more layers using techniques such as dropletdispense, spin-coating, dip coating, chemical vapor deposition (CVD),physical vapor deposition (PVD), thin film deposition, thick filmdeposition, or combinations thereof. The formable material 34 can bedispensed upon the substrate 12 before or after a desired volume isdefined between the mold 20 and the substrate 12, depending on designconsiderations. For example, the formable material 34 can include amonomer mixture that can be cured using ultraviolet light, heat, or thelike.

The lithographic system 10 can further include an energy source 38coupled to a direct energy 40 along a path 42. The imprint head 30 andstage 16 can be configured to position the template 18 and substrate 12in superimposition with the path 42. The lithographic system 10 can beregulated by a logic element 54 in communication with the stage 16,imprint head 30, fluid dispense system 32, or source 38, and may operateon a computer readable program, optionally stored in memory 56. Thelogic element 54 may be a processor (for example, a central processingunit of a microprocessor or microcontroller), a field-programmable gatearray (FPGA), an application specific integrated circuit (ASIC), or thelike. The processor, FPGA, or ASIC can be within the apparatus. Inanother embodiment (not illustrated), the logic element can be acomputer external to the apparatus 10 and is bidirectionally coupled tothe apparatus 10.

While the formation of a patterned layer over the substrate 12 using theformable material 34 is relatively simple on a conceptual basis, thepatterned layer is significantly difficult, particularly in view of thesmall dimensions, avoiding direct contact between the template 18 andthe substrate 12, and desire for high throughput for the apparatus 10.In this specification, new fluid droplet patterns can be used to achieverelatively high volume production for the apparatus and withoutincreasing defects, such as extrusion defects.

U.S. Pat. No. 8,556,616 illustrates a fluid droplet pattern and how thefluid droplets coalesce when a template contacts the fluid droplets. Inparticular, FIG. 9 of U.S. Pat. No. 8,556,616 illustrates a fluiddroplet pattern before a template contacts the fluid droplets 54. FIGS.17 to 20 of U.S. Pat. No. 8,556,616 include illustrations of how thefluid droplets 54 coalesce and form an interface 88, which represents afluid front, that moves from the center of an imprint field radiallyoutward at different points in time. As can be seen in FIG. 20, theinterface 88 reaches centers along the sides of the imprint field beforereaching corners of the imprint field. By the time the interface 88moves significantly closer to the corners (at a point in time later thanFIG. 20), the likelihood of an extrusion defect near the center of anyone or more of the sides is significantly higher.

An extrusion defect is a portion of a resist layer that extends beyondany side of the mold 20 during the imprint process. Before theinventors' discovery, uniform DEEs were used along a side of an imprintfield resulting in a DEZ having a uniform width. The distances for DEEsmay be made uniformly larger or uniformly smaller; however, suchalternatives have other consequences. To minimize extrusions at the edgecenter regions, larger DEEs, an earlier cure of the formable material,or both can be used, but such a change may significantly increase a riskof having more non-fill defects in the corner areas because those areasmay not have had sufficient time for adequate droplet spreading andfilling. If smaller DEEs, waiting for more filling to occur in thecorner areas, or both are used, such a change may significantly increasethe risk of more extrusion defects at the edge center regions.

The inventors have discovered that a fluid droplet pattern can usevariable DEEs resulting in a DEZ that is indented farther into theimprint field closer to a centerpoint along a side of the imprint field.Thus, a portion of DEZ is wider and the distances for the correspondingDEEs are longer near the centerpoint of the side of the imprint field,as compared to another portion of the DEZ and corresponding DEEs fartherfrom the centerpoint. The pattern helps to flow fluid droplets of aformable material 34, so that the formable material 34 reaches allpoints of the template 18 along a side of the imprint field closer intime as compared to one another without significantly increasing therisk of forming an extrusion defect.

In essence, when using variable DEEs, the fluid droplet placement bettersynchronizes the spreading/filling along the entirety of the field edge(from center edge outward to corners) as compared to droplet patternhaving a uniform width of the DEZ and uniform distances for the DEEsalong the side of the imprint field. Thus, a variable DEE approach, whenused with a center-to-perimeter template-substrate contact scheme,provides for a better balance of extrusion control (near the centers ofthe field edges) vs. non-fill control (at the field corners).

FIG. 2 illustrates a portion of a fluid droplet pattern 300. The fluiddroplet pattern 300 of fluid droplets 302 of the formable material 34 isdisposed within an imprint field. The imprint field has a side 340 and aDEZ along the side 340. In an embodiment, the fluid droplet pattern 300is organized in rows, and each row includes a terminal fluid dropletalong a boundary of the DEZ. The rows of the fluid droplet pattern 300extend in a translating direction, which is the direction in which thesubstrate 12 and the template 18 move relative to each other. Fluiddroplets 302 are dispensed in the translating direction at a translatingfluid droplet pitch. As used in this specification, the translatingdirection is referred as the x-direction, and the translating fluiddroplet pitch is an X-direction pitch.

The DEZ is the area between the side 340 and the dashed line 320 thatpasses though the terminal fluid droplets, including terminal fluiddroplets 322, 324, and 326. For the fluid droplet pattern 300illustrated in FIG. 2, the terminal fluid droplets 322, 324, and 326have corresponding DEEs 362, 364, and 366, respectively. The DEZ isnarrower farther from the center of the side 340 and wider closer to thecenter of the side 340. The DEE 364 corresponding to the terminal fluiddroplet 324 is greater than each of the DEEs 362 and 366 correspondingto the terminal fluid droplets 322 and 326. The difference between theDEE 364 and each of the DEEs 362 and 366 is less than the translatingdirection (x-direction) pitch. In another embodiment, the differencebetween the DEE 364 and each of the DEEs 362 and 366 may be the same orgreater than the translating direction (x-direction) pitch.

As will be described in more detail later in this specification, thefluid droplet pattern 300 can be formed by rotating a fluid dispenser, asubstrate, or both. In an embodiment, the rotation may be performed sothat it is at most the same as the x-direction pitch. For example, thefluid droplet pattern 300 corresponds to a rotational angle of 2milliradians (mrads) when the distance between the centers of the fluiddroplets 322 and 326 is approximately 33 mm. The DEE 364 is 210 microns,and the DEEs 362 and 366 are 175 microns. Thus, the difference in DEEsis 35 microns in this particular embodiment.

FIG. 3 illustrates a portion of a fluid droplet pattern 400 and acorresponding set of photographs of a resist layer as seen through theimprint template 18. The fluid droplet pattern 400 of fluid droplets 402of the formable material 34 is disposed within an imprint field. Theimprint field has a side 440 and a DEZ along the side 440. In anembodiment, the fluid droplet pattern 400 is organized in rows, and eachrow includes a terminal fluid droplet along a boundary of the DEZ. Therows of the fluid droplet pattern 400 extend in a translating direction,which is the direction in which the substrate 12 and the template 18move relative to each other. Fluid droplets 402 are dispensed in thetranslating direction at a translating fluid droplet pitch. As used inthis specification, the translating direction is referred as thex-direction, and the translating fluid droplet pitch is an X-directionpitch.

The DEZ is the region between the side 440 and the dashed line 420 thatpasses through the terminal fluid droplets, including terminal fluiddroplets 422, 424, and 426. For the fluid droplet pattern 400illustrated in FIG. 3, the terminal fluid droplets 422, 424, and 426have corresponding DEEs 462, 464, and 466, respectively, that areuniform. Unlike FIG. 2, in FIG. 3, the DEZ has a substantially uniformwidth along the side 440.

In FIG. 3, the fluid droplet pattern 400 corresponds to a rotationalangle of zero. In other words, the substrate and fluid dropletdispenser(s) is (are) not rotated relative to each other. The distances462, 464, and 466 along the side 440 are all 180 microns. Thus, thedifferences in DEEs are zero.

The amount of rotation and indentation may depend on the pattern ofrecessions and protrusions along the imprint surface 22 of the template18. When imprinting using the fluid droplet patterns 300 and 400, acamera or another visual tool may be used to monitor how the fluid frontis progressing from the center of the imprint fields to the edges of theimprint fields. Alternatively or in conjunction with the camera orvisual tool during imprinting, the formable material may be cured, andthe printed and inspected for the presence and location of non-filldefects and extrusion defects. Ideally, there are not any non-filldefects extrusion defects for a particular rotation, and such rotationmay be used. If there are extrusion defects at any of the corners,non-fill defects near a centerpoints of the edges, or both, the rotationmay be adjusted to a lower value. Thus based information gathered, theangle of rotation may be determined.

The indentation of the DEZ along sides of the imprint field can beobtained using different equipment configurations and techniques, someof which are described and illustrated herein. After reading thisspecification, skilled artisans will appreciate that other embodimentscan be used without departing from the concepts as described here. Anexemplary fluid dispenser is illustrated in FIG. 4 before addressingother aspects of the equipment configurations and technique asillustrated in FIGS. 5 to 12. In FIGS. 5 to 12, not all fluid dropletsare illustrated to aid in understanding the concepts, and therefore,only those fluid droplets near the sides are illustrated.

FIG. 4 includes a side view of a portion of a fluid dispenser 500. Thefluid dispenser 500 includes fluid dispense ports 520 through which theformable material is dispensed. The fluid dispense ports 520 areoriented along one or more lines that are substantially parallel to thelength of the fluid dispenser 500. Any one or more of the embodimentsdescribed below can use the fluid dispenser 500.

FIG. 5 includes an illustration of a portion of a fluid dispense pattern600 in accordance with an embodiment in which fluid dispensers 610 and620 are rotated with respect to a side 640, and the fluid dropletpattern 600 is formed with a single pass. Referring to FIG. 5, the fluiddispense system 32 includes the fluid dispenser 610 and the fluiddispenser 620, and the fluid dispensers 610 and 620 are oriented indifferent rotational directions with respect to the side 640 of theimprint field. In a particular embodiment, the fluid dispenser 610 isrotated counterclockwise with respect to the side 640, and the fluiddispenser 620 is rotated clockwise with respect to the side 640. Thefluid dispensers 610 and 620 rotate with small positive and smallnegative angles relative to the side 640 of the imprint field, and thefluid droplet pattern 600 can be achieved with a single pass as shown inFIG. 5. In the embodiment as illustrated, the dispensers 610 and 620remain at substantially the same relative angle during a single pass.The upper left and lower right quadrants of fluid droplets are formedusing the fluid dispenser 610, and the lower left and upper rightquadrants of fluid droplets are formed using the fluid dispenser 620.

FIG. 6 includes an illustration of a portion of a fluid dispense pattern700 in accordance with an embodiment in which the fluid dispense system32 includes a fluid dispenser 710 that is rotated one way relative tothe side 740 for one pass and rotated the other way to the side 730 forthe other pass. The angle of rotation may or may not be the same.Relative to the side 740, the fluid dispenser 710 rotates clockwise in apositive angle in the first pass, and rotates counterclockwise in anegative angle in the second pass to form the fluid droplet pattern 700.In particular, fluid droplets in the lower left and upper rightquadrants are formed during one pass, the angle of rotation of the fluiddispenser is changed, and then fluid droplets in the lower right andupper left quadrants are formed during the other pass.

FIG. 7 has an equipment configuration similar to FIG. 6. FIG. 7 can beuseful when all sides, rather than just two opposing sides, haveindentations for the DEZs. In the embodiment illustrated in FIG. 7, thesubstrate 12, rather than the fluid dispenser 810, is rotated whengenerating the fluid droplet pattern 800. The fluid dispenser 810remains fixed (no rotation) during two different passes, where thesubstrate 12 rotates in small positive and negative angles between thetwo different passes.

FIG. 8 includes an illustration of a more complex equipmentconfiguration in which different fluid dispensers 910 and 920 thatextend along lengths that are oriented along adjacent sides of theimprint field 900. The fluid dispenser 910 is positioned along one sideof the imprint field perpendicular to the dispense scan direction(X-direction) and forms fluid droplets 912 during one scan. The fluiddispenser 920 is positioned along another side of the imprint field andforms fluid droplets 922 during another scan. Lengths of the fluiddispensers 910 and 920 are along lines that intersect at an angle otherthan 90°. The substrate is rotated with respect to both fluid dispensers910 and 920. In other words, the lengths of the fluid dispensers 910 and920 are not parallel with their corresponding sides.

In one or more of the previous embodiments, portions of the fluiddroplet pattern may be stitched together to keep the fluid droplet pitchmore uniform in the translating direction. The embodiment illustrated inFIG. 9 can be formed similar to the embodiment as described with respectto FIG. 5. FIG. 9 illustrates the fluid dispensers 1010 and 1020 aspreviously described and includes a fluid droplet pattern 1000 for animprint field having fluid droplets from different quadrants stitchedtogether in accordance with an embodiment. The two quadrants of fluiddroplet along the upper side and the two quadrants of fluid dropletalong the lower side are relatively close to each other near the centerof the fluid droplet pattern 1000. Without stitching, significant gapsbetween the fluid droplet quadrants along the upper and lower sides mayoccur. On an intra-row basis, stitching allows the fluid droplets alonga row to have spacings more consistent with the fluid droplet pitch andhave a predetermined local volume of the formable material. Stitchingcan be useful when more than one fluid dispenser or more than one passis used to generate a fluid droplet pattern.

In prior embodiments, the fluid dispenser, the substrate, or both can berotated in an X-Y plane. In such embodiments, the spacing between thefluid dispenser and substrate is substantially uniform. In furtherembodiments, the fluid dispenser, the substrate, or both may be rotatedin a Y-Z plane, such that the spacing between the fluid dispenser andsubstrate vary along the length of the fluid dispense. For example, oneend of the fluid dispenser may be closer to the substrate as compared tothe other end of the fluid dispenser. The spacing may becomeprogressively larger as the distance from the one end to the other endincreases. The dispenser, the substrate or both may pivot about acenterline that is substantially perpendicular to the length of thefluid dispenser or may pivot about a point at or closer to an end of thefluid dispenser. In FIGS. 10 to 12, no rotation in the X-Y plane isrequired. The lengths of the fluid dispensers can be substantiallyparallel to the sides of the imprint fields.

FIG. 10 includes an illustration of an imprint field 1100 during theformation of a fluid droplet pattern. In FIG. 10, a single fluiddispenser 1160 can be used with different rotations during differentpasses. During a first pass, the fluid dispenser 1160 and the substrateare oriented such that a location 1162 represents a farther distancebetween the fluid dispenser 1160 and the substrate, and a location 1164represents a closer distance between the fluid dispenser 1160 and thesubstrate. During the first pass, sets 1102 and 1104 of fluid dropletsare dispensed onto the substrate within the imprint field 1100. Afterthe first pass, the orientation remains the same, such that the location1162 represents a farther distance between the fluid dispenser 1160 andthe substrate, and the location 1164 represents a closer distancebetween the fluid dispenser 1160 and the substrate. During a secondpass, sets 1106 and 1108 of fluid droplets are dispensed onto thesubstrate within the imprint field 1100. Thus, FIG. 10 illustratesanother method of achieving the fluid droplet pattern as illustrated inFIG. 9.

FIG. 11 includes an illustration of an imprint field 1200 during theformation of a fluid droplet pattern. In FIG. 11, a single fluiddispenser 1260 can be used with rotation occurring during each passes.At the beginning of a first pass, the fluid dispenser 1260 and thesubstrate are oriented such that a location 1262 represents a fartherdistance between the fluid dispenser 1260 and the substrate, and alocation 1264 represents a closer distance between the fluid dispenser1260 and the substrate. During the first pass, the dispenser 1260 isrotated about an axis illustrated by a dashed line. At the end of thefirst pass, the fluid dispenser 1260 and the substrate are oriented suchthat a location 1266 represents a closer distance between the fluiddispenser 1260 and the substrate, and a location 1268 represents afarther distance between the fluid dispenser 1260 and the substrate. Aset 1202 of fluid droplets is dispensed onto the substrate within theimprint field 1200. During a second pass, the rotation is reversed. Atthe beginning of the second pass, the fluid dispenser 1260 and thesubstrate are oriented such that a location 1282 represents a closerdistance between the fluid dispenser 1260 and the substrate, and alocation 1284 represents a farther distance between the fluid dispenser1260 and the substrate. During the second pass, the dispenser 1260 isrotated about the axis illustrated by the dashed line. At the end of thesecond pass, the fluid dispenser 1260 and the substrate are orientedsuch that a location 1286 represents a farther distance between thefluid dispenser 1260 and the substrate, and a location 1288 represents acloser distance between the fluid dispenser 1260 and the substrate. Aset 1206 of fluid droplets is dispensed onto the substrate within theimprint field 1200.

FIG. 12 includes an illustration of an imprint field 1300 during theformation of a fluid droplet pattern. In FIG. 12, a pair of fluiddispensers 1320 and 1340 can be rotated to form the fluid dropletpattern in a single pass. At the beginning of the pass, the fluiddispenser 1320 and the substrate are oriented such that a location 1322represents a closer distance between the fluid dispenser 1320 and thesubstrate, and a location 1324 represents a farther distance between thefluid dispenser 1320 and the substrate; and the fluid dispenser 1340 andthe substrate are oriented such that a location 1346 represents a closerdistance between the fluid dispenser 1320 and the substrate, and alocation 1348 represents a farther distance between the fluid dispenser1340 and the substrate. In FIG. 12, a set 1302 of fluid droplets isdispensed onto the substrate by the dispenser 1320 using ports closer tothe location 1322, a set 1304 of fluid droplets is dispensed onto thesubstrate by the dispenser 1320 using ports closer to the location 1324,a set 1306 of fluid droplets is dispensed onto the substrate by thedispenser 1340 using ports closer to the location 1346, a set 1308 offluid droplets is dispensed onto the substrate by the dispenser 1340using ports closer to the location 1348. Thus, FIG. 12 illustratesanother method of achieving the fluid droplet pattern as illustrated inFIG. 9.

In accordance with an embodiment described herein, FIG. 13 includes aflow chart for a method that can be used forming a substrate fluiddroplet pattern for an imprint lithography process. The method is betterunderstood with respect to the apparatus 10 in FIG. 1 and fluiddispenser and substrate orientations previously described. The methodcan include providing a fluid dispenser including a set of fluiddispense ports, at block 1402. In an embodiment, the method can beperformed by an imprint lithography apparatus including a fluid dispensesystem, a stage, and a logic element.

The method can further include generating a fluid droplet pattern offluid droplets of a formable material, at block 1422. At this point inthe process, the fluid droplet pattern can be virtual pattern generatedby the logic element. The logic element can include hardware, firmware,software, or any combination thereof to perform many of the operationsdescribed herein. In a particular embodiment, the logic element can bethe processor 54. The fluid droplet pattern can be any of the patternsas previously described. The logic element may use a hardware andprocessing description of the apparatus 10 when determining the fluiddroplet pattern. The hardware and processing description can include thenumber of fluid dispensers; when there are at least two fluiddispensers, the positions of the fluid dispensers relative to each otherand the substrate; whether the one or more fluid dispensers or thesubstrate is rotated; the number of passes used to generate the fluiddispense pattern; the direction of motion of the substrate and fluiddispensers relative to one another; whether any fluid dispenser isrotated between passes; or the like.

A substrate can be placed on the stage, and in an embodiment, thesubstrate can be a semiconductor wafer. The method can further includemoving the substrate and the set of the fluid dispense ports relative toeach other, at block 1424, and dispensing fluid droplets of the formablematerial onto the substrate, at block 1426. After the substrate and theset of the fluid dispense ports start moving, the fluid droplets aredispensed onto the substrate to achieve a physical instantiation of thefluid droplet pattern corresponding to the virtual instantiation of thefluid droplet pattern generated by the logic element. Referring to FIG.1, the processor can generate instructions that are transmitted to theimprint head 30 and the fluid dispense system 32 potentially, and astage controller (not illustrated). The fluid dispense system can rotatethe fluid dispenser or fluid dispenser, control movement of the fluiddispenser, and control dispensing of fluid droplets. The stagecontroller may rotate the substrate or move the substrate along one ormore directions. After reading this specification, skilled artisans willappreciate that rotation and movement during a pass may achieved bymoving the fluid dispenser, the substrate, or both the fluid dispenserand the substrate.

At block 1442, the method can include contacting the formable materialwith the template. Referring to FIG.1, the imprint head 30, the stage16, or both the imprint head 30 and the stage 16 vary a distance betweenthe mold 20 and the substrate 12 to define a desired volume therebetweenthat is filled by the formable material 34. For example, the imprinthead 30 can apply a force to the template 18, such that the mold 20contacts the formable material 34 on the substrate 12. In an embodiment,the patterned surface has projections and recessions, and in anotherembodiment, the patterned surface can be a blank (a flat surface withoutany projections or recessions). The fluid droplet pattern allows theformable material to reach its desired locations more quickly along thesides of the imprint field without a significant risk of forming anextrusion defect.

At block 1444, the method includes curing the formable material to forma patterned layer corresponding to the pattern surface of the template.Curing can be performed by exposure to electromagnetic radiation. In anembodiment, the electromagnetic radiation can be ultraviolet radiation.In another embodiment, the formable material can be cured using heat.The patterned layer on the substrate has a complementary pattern ascompared to the patterned surface of the template. Projections along thepatterned layer correspond to recessions in the patterned surface of thetemplate, and recessions in the patterned layer correspond toprojections along the patterned surface of the template. The recessionsin the patterned layer are parts of a residual layer having a residuallayer thickness.

The methods can be useful in manufacturing an article that includes asubstrate, such as an electronic component that includes part of asemiconductor wafer.

Many operations have been described with respect to particularcomponents within the apparatus 10. In particular embodiment, operationsperformed by a logic element, which may be at least a part of theprocessor 54, may be performed by other components within the apparatus10 or split between the processor 54 and such other components. Forexample, some operations previously described as being performed by theprocessor 54 may be performed by a stage controller that controls theoperation of the stage 16, the fluid dispense system 32, a fluiddispenser controller that controls fluid dispenser. Furthermore,information can be transmitted in order to carry out the actionsdescribed herein. The information can be in the form of instructions tobe executed, signals, pulses, or the like. The stage 16, the fluiddispense system 32, or both may include a controller that can act oninstructions received from the processor 54. In another embodiment, thestage 16 or the fluid dispense system 32 may respond to analog signalsreceived. For example, the information can be a particular directcurrent voltage or a light pulse. After reading this specification,skilled artisans will be able to configure an imprint lithographyapparatus 10 to meet the needs or desires in view of the equipmentwithin the apparatus 10. Thus, the description of the embodiments doesnot limit the scope of the present invention.

Embodiments of the apparatuses and method can be useful in filling animprint field relatively quickly without extrusion defects or othercomplications. A virtual fluid droplet pattern can be generated by alogic element, such as a processor within a lithographic tool, to tailorthe shape of the DEZ for a particular imprint surface of a template.Instructions corresponding to the virtual patterned can provided to afluid dispense system in forming an actual fluid droplet pattern. Thefluid droplet pattern can allow a formable material to reach pointsalong sides of an imprint closer in time as compared to conventionaltechniques. The indentations of the patterns along sides help to keepthe likelihood of forming an extrusion defect significantly low.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed is not necessarily the order inwhich they are performed.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The specification and illustrations of the embodiments described hereinare intended to provide a general understanding of the structure of thevarious embodiments. The specification and illustrations are notintended to serve as an exhaustive and comprehensive description of allof the elements and features of apparatus and systems that use thestructures or methods described herein. Separate embodiments may also beprovided in combination in a single embodiment, and conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.Further, reference to values stated in ranges includes each and everyvalue within that range. Many other embodiments may be apparent toskilled artisans only after reading this specification. Otherembodiments may be used and derived from the disclosure, such that astructural substitution, logical substitution, or another change may bemade without departing from the scope of the disclosure. Accordingly,the disclosure is to be regarded as illustrative rather thanrestrictive.

What is claimed is:
 1. An apparatus for imprint lithography comprising alogic element configured to generate a fluid droplet pattern of fluiddroplets of a formable material to be dispensed onto a substrate,wherein the fluid droplet pattern includes an imprint field, wherein:the imprint field has a side and a drop exclusion zone along the side;and the drop exclusion zone is narrower at a first point farther from acenter of the side and wider at a second point closer to the center ofthe side.
 2. The apparatus of claim 1, wherein the fluid droplet patternis organized in rows, wherein each row includes a terminal fluid dropletalong a boundary of the drop exclusion zone.
 3. The apparatus of claim2, wherein: a first terminal fluid droplet is along a first row, and asecond terminal fluid droplet is along a second row; the center of theside of the imprint field is closer to the second terminal fluid dropletthan to the first terminal fluid droplet; and the first terminal fluiddroplet has a corresponding first DEE, and the second terminal fluiddroplet has a corresponding second DEE that is longer than the firstDEE.
 4. The apparatus of claim 3, wherein: the fluid droplet pattern isarranged in rows that extend in a translating direction and has atranslating fluid droplet pitch; and a difference between the second andfirst DEEs is less than the translating fluid droplet pitch.
 5. Theapparatus of claim 1, wherein an angle between the side of the imprintfield and a length of a fluid dispenser is configured to be changedduring a pass or between different passes.
 6. The apparatus of claim 5,wherein a fluid dispense system comprises a first fluid dispenser and asecond fluid dispenser.
 7. The apparatus of claim 6, wherein the firstand second fluid dispensers are in different rotational directions withrespect to the side of the imprint field.
 8. The apparatus of claim 6,wherein the first fluid dispenser and the second fluid dispenser arealong different sides of the imprint field.
 9. The apparatus of claim 6,wherein the first fluid dispenser and the second fluid dispenser arealong adjacent sides of the imprint field.
 10. The apparatus of claim 9,wherein: the first fluid dispenser has a length that lies along a firstline; the second fluid dispenser has a length that lies along a secondline; and the first and second lines intersect at an angle other than90°.
 11. An imprint lithography method, the method comprising:generating a fluid droplet pattern of fluid droplets of a formablematerial to be dispensed onto a substrate, wherein the fluid dropletpattern includes an imprint field, wherein: the imprint field has a sideand a drop exclusion zone along the side; and the drop exclusion zone isnarrower at a first point farther from a center of the side and wider ata second point closer to the center of the side; and dispensing fluiddroplets of the formable material onto the substrate corresponding tothe fluid droplet pattern.
 12. The method of claim 11, whereindispensing the fluid droplets of the formable material is performedduring a single pass using a first fluid dispenser and a second fluiddispenser that are in different rotational positions with respect toeach other.
 13. The method of claim 11, wherein dispensing the fluiddroplets of the formable material comprises: dispensing a first set ofthe fluid droplets using a fluid dispenser during a first pass; rotatingthe fluid dispenser, the substrate, or both; and dispensing a second setof the fluid droplets using the fluid dispenser during a second pass.14. The method of claim 11, wherein dispensing the fluid droplets of theformable material comprises: dispensing a first set of the fluiddroplets using a first fluid dispenser and a second set of fluiddroplets using a second fluid dispenser during a pass; and rotating thefirst fluid dispenser, the second fluid dispenser, the substrate or anycombination during the pass.
 15. The method of claim 11, furthercomprising providing an apparatus having a fluid dispense system thatincludes a first fluid dispenser and a second fluid dispenser, wherein:the first fluid dispenser and the second fluid dispenser are orientedalong adjacent sides of the imprint field before dispensing the fluiddroplets; the first fluid dispenser has a length that lies along a firstline; the second fluid dispenser has a length that lies along a secondline; and the first and second lines intersect at an angle other than90°.
 16. The method of claim 15, wherein dispensing the fluid dropletsof the formable material comprises: dispensing a first set of the fluiddroplets using the first fluid dispenser; and dispensing a second set ofthe fluid droplets using the second fluid dispenser.
 17. The method ofclaim 11, wherein generating the fluid droplet pattern is performed suchthat, wherein on an intra-row basis, fluid droplets from each of firstand second passes or different fluid dispensers along a row has apredetermined local volume of the formable material.
 18. The method ofclaim 17, wherein the fluid droplets from the first and second passesmeet at a junction that is spaced apart from a central portion of theimprint field.
 19. A method of manufacturing an article, the methodcomprising: providing a fluid dispense system having fluid dispenseports; generating a fluid droplet pattern of fluid droplets of aformable material to be dispensed onto a substrate, wherein the fluiddroplet pattern includes an imprint field, wherein: the imprint fieldhas a side and a drop exclusion zone along the side; and the dropexclusion zone is narrower at a first point farther from a center of theside and wider at a second point closer to the center of the side; andmoving a substrate of the article and the fluid dispense ports relativeto each other; dispensing fluid droplets of the formable material ontothe substrate corresponding to the fluid droplet pattern; contacting theformable material with the template having a patterned surface; andcuring the formable material to form a patterned layer corresponding tothe patterned surface of the template.
 20. The method of claim 19,wherein the article includes an electronic device, and the substrateincludes a semiconductor wafer.